Understudy
by DaughterOfStarlight
Summary: Destiel Musical Theater AU. When leading tenor Dean Winchester comes down with a case of mono right before opening night, his shy friend Cas fills in as Danny in Grease. The show brings them both out of their shells in unexpected ways. Oneshot, Sammy guest appearance, sweet as can be.


**It's fluffy crack, I know, but that's sort of the point. This is for all my thespians out there.**

"Now this car is automatic," Dean purred as he hopped off the muscle car set and began his choreographed stroll upstage. "It's hydromatic. It's systematic…" His leather T-birds jacket hit the floor as he snapped his fingers, queuing up the rockabilly accompaniment and summoning his back up dancers. "Why it's greased lightning!"

The stage burst to life with the boisterous energy of the male ensemble shouting lyrics back and forth and sliding across the polished floorboards. The lights flickered and panned randomly as the techies in the sound booth ran diagnostics and the director dictated to his assistant as she sat in the audience, unforgivingly critical. It was dress rehearsal for the Bella Donna theatre's season opener_, Grease_. The Bella Donna didn't tackle musicals often, but when they did they were always pitch-perfect, and this show wasn't going to be the exception to the rule if administration had anything to say about it. Things were going fairly well; the company was splendid, the set looked great, and the casting was airtight.

There was just one problem. Dean Winchester, leading man for his fourth season in a row, was slowly but surely coming down with a case of mono. Not that he was going to tell anyone that, not over his dead body. There simply was no getting sick this late in the game, and if he pulled a stunt like that he was likely to not get cast as favorably next year. That damn director held grudges. Wasn't it time for him to retire?

"SMILE!" The director roared, and Dean, who realized he had let his face slip into an introspective expression as he pondered his fate if his illness flared up, plastered a camera-ready grin across his face and tried to make eye contact with the other guys on stage. There was Billy, decent enough fella, Jacob, who hated him with all the passion of a perpetual supporting actor, Ryan, who never talked, Sam, who was close to him as a brother, and Cas….Cas.

Dean allowed himself to be distracted during an instrumental bridge by the other man's angelic blue eyes and forever mussed hair. Cas, who spoke in adorably shy compliments and encouragements. Cas, who always had a megawatt smile for Dean while they were sitting through the grueling hour of hair and makeup. Cas, who was loyal to a fault, feisty when cornered, and more loving than Dean thought anyone could ever be.

Dean came in on his solo a beat late. Damn it, Cas.

They had been fast friends since getting thrown together during their first show together at Bella Donna (_Death of a Salesman_? No, _Hamlet_. That was the season they spent insulting each other in Shakespearean slang) and if Dean was being perfectly honest the idea of being something more had crept into his mind on a couple of emotional or drunk or otherwise ill-advised occasions. But Cas rarely showed interest in anyone around the theater and so Dean had no idea what the Hell he liked. He knew the other man didn't have a significant other but he just didn't have the heart to ask him which way he swung, not after five years of friendship. It had never mattered before and didn't matter now…But Dean was so painfully curious. Not that knowing either way would change anything, Cas was only a friend, he _had_ to be only a friend…Oh, but Dean was curious.

As if on cue, the brunette caught Dean's eye as he sang his bit of the song, and Dean felt himself go weak in the knees. He had a strong rock tenor that got him cast in damn near everything, but Cas's silky baritone was one of the most gorgeous voices Dean had ever heard. He was convinced his friend could land any role he wanted if he came out of his shell a little, but Cas kept to himself, and though he loved performing, wasn't overly fond of the limelight.

Without pretense, Dean winked at him and Cas suddenly forgot the next step, nearly crashing into the extra to his right. Dean saved him by grabbing his wrist and twirling him expectedly out of the collision course, laughing too low for his mic to pick it up. Cas blushed furiously, giving Dean great pleasure, then threw himself into the dance with a little too much gusto.

_Maybe he's not quite straight as an arrow,_ Dean mused to himself, then belted the next verse.

And failed miserably.

His voice cracked, cutting the line short and sending Dean's hand up to clutch his aching throat. That was it. The final ounce he had left to give. His voice was officially shot and would be until this damn mono had passed.

"STOP!" The director cried, standing up in her seat in the audience. The orchestra trailed off and the boys on stage wound down, panting and confused. A few shot Dean dirty looks. It took a lot to stop a dress rehearsal, and it usually meant more time drilling a shaky scene.

"What the Hell was that?" She demanded.

Dean tried to think on his feet, tapping the microphone taped to his cheek. "Mic crapped out, some sort of whacked radio interference. Ask sound, I dunno-"  
The director wasn't having it. "Are you sick?"

"What? Pffft, no. Well, I mean…Yeah, okay, a little. Just a cold…Ish flu type thing…Well It's really more of…Mono. I have mono."

The entire stage dissolved into groans and whimpers. The director threw her notes into the air, screamed at her assistant to change the name on the programs, then fumed for a moment before turning to Dean.

"Go home, Dean."

The thirty-year old bristled. "What? No, I can sing this role, I feel fine-"

"GO HOME. You're going to give it to the whole damn cast and kill yourself in the process. You need medicine and bed rest."

"Like Hell I do! I need to open this show!"

"Don't talk back Winchester, or as God as my witness I'll never cast you in a show again. Leave, go. We'll clean up the mess here. CAS!"

Cas, who never really understood why the director felt the need to shout everything, stepped up and stood awkwardly next to Dean downstage center.

"Uhm…Yes Ma'am?"

"You're the understudy, right?"  
"Technically, I suppose that's accurate…"

"You know Dean's part?"

"Of course."

"Go to wardrobe, get outfitted for Danny, I want everyone back on stage in ten minuets. We're running the show from the top with Cas filling in for Dean and anyone who says otherwise is dead. You hear me? Dead!"

Everyone on stage scattered, off to gossip and grab a bite to ear and smoke behind the buildings. Only Dean and Cas remained, staring dumbstruck at each other. Dean looked like someone had stolen his puppy. Cas looked like someone had told him he had until curtain on opening night to live. Still, he reached out a squeezed Dean's fingers. An intimate gesture, sure, but they both needed it.

"It's going to be fine. You'll be well in time."

Dean did the math. Three days away. He smiled at his friend bitterly, kissing his hand before dropping it and shoving his hands in his pockets.

"No I won't. You've gotta open this show, Cas."

Cas paled. Dean sighed and trudged backstage, going to turn in his leather jacket for the time being.

Three nights later, Dean blatantly disobeyed his doctor's orders and snuck out to go watch the show. Not in the audience, that would be too obvious. Instead, he slid in through the backstage door and hid in plain sight, guzzling vitamin-spiked orange juice as he watched from the wings and gnawed nervously at his lip. Sam caught him during _Hopelessly Devoted to You_ and poked him in the shoulder blades.

"What are you doing here, Dean? The dragon lady'll kill you if she sees you out of bed."

"Screw her," Dean mumbled in a whisper. "This show is my baby and Cas is my friend, I'm going to watch it!"

Sam brooded a bit as he re-taped his mic and waited impatiently for his cue, but didn't rat Dean out. So far, nobody had noticed an out-of place civilian lurking in the wings, and if Sam had anything to say about it, nobody would. The taller man screwed a black technical support baseball cap on his friend's head and he prepared to sprint onstage.

"Keep your head down."

Dean grinned rakishly, picking up a tech headset and listening in on the backstage directions and cast chatter. "Thanks man."

"Oh, and try not to droll. Your boy's in fine form tonight."  
Dean's sense of masculinity bristled. "What're you getting at, Sammy?"

Sam made a disgusted noise. "Seriously? You'd burn holes through Cas if you stared at him with any more longing, and I could choke on all the sweetness and devotion he addresses you with. Get a room, would you? The whole cast knows. And don't call me Sammy!"

"Bitch."

"Jerk," Sam laughed, then darted out onto the stage, already belting his next line.

And so Dean watched the show. And man alive, did Cas bring it. Dean knew the guy was talented; he had heard him at auditions and with the other stage rats at cast parties, but this was on a completely different level. God, that _voice_. Not to mention the fact that he was buzzing with kinetic energy and cheeky snark, and his lines were delivered with enough deadpan eagerness to make even the most critical audience member chuckle a bit. Oh, and the sex appeal. Dean had thought he had a corner on the heartthrob market, but Cas in a leather jacket was enough to nudge the MPAA rating of this show up a few points. It took Dean a few musicals to realize that he was extremely biased in this department, more so than he originally thought, and said goodbye to whatever was left of his heterosexuality with a muttered curse and flushed cheek.

All in all, the show was an absolute knockout. Dean was already clapping halfway through _You're the One that I Want_ and didn't stop until the fifth curtain call. He waited impatiently for Cas to finally dart offstage, grinning wildly behind his greasepaint and high on after-show adrenaline, then caught the new leading man behind the neck and slammed his mouth into his. Cas made a surprised noise, then laughed in triumph and tangled his fingers in Dean's hair, kissing the other man back with a hungry grin. When Dean finally came up for air, terrified that he had ruined their friendship, the glow in those blue eyes put his head at rest. Cas spread his arms wide.

"Well?"

"You kicked ass!"

"The show pleased you? I did the best I could, I'm not you…I was pitchy in act two I know, but I think the last number was really quite good, and very enjoyable-"

Dean silenced his self-criticism with another kiss. The rest of the cast applauded, then begrudgingly forked over their will-they-or-won't-they bets to a grinning Sam, who wasn't a gambling man unless he was absolutely sure.

Dean and Cas lost themselves for a moment, then pulled apart with a start when a harsh throat was cleared behind them. The stagemanager was glaring at them with the very fire of Hell in his eyes.

"Are you insane?" He hissed, gesturing violently to Dean. "You have mono! You're _contagious_!"

Dean and Cas stared at each other in shock for a moment, then Cas realized the implications of this and darted away into a frantic search for mouthwash and vitamins. In his absence, Dean grinned to himself.

"Worth it."


End file.
